Impact of exogenous Lactobacillus plantarum on the gut microbiome of hematopoietic stem cell transplantation patients colonized by multi-drug resistant bacteria: An exploratory study

Previous gut colonization by multidrug resistant organisms is a risk factor for bloodstream infections and a major complication in the early phase of Hematopoietic Stem Cell Transplantation. We evaluated, in an exploratory study, the impact of Lactobacillus plantarum on modulation of the gut microbiome in HSCT patients colonized by MDROs.Stool samples were obtained at timed intervals from 42 oncohematological candidates undergoing autologous or allogeneic HSCT. Participants were allocated to an intervention group who received capsules of L. plantarum twice a day before the HSCT until the onset of neutropenia and a control group. The V4 region of the 16S bacterial rRNA gene in 93 stool samples from a subset of 33 patients was sequenced.L. plantarum had an average 86 percent drug-target engagement at 43 days of consumption and it was safe, tolerable and associated with an increase in the abundance of the Lactobacillales. Differently abundant bacteria were investigated by LefSe and an increase of Lactococcus and reduction of Turicibacter were identified on the second-week of L.plantarum use. Both the IG and CG exhibited a similar reduction in MDROs; except Enterococcus abundance which had a greater rise in the CG Alpha and beta diversity measures were altered throughout the HSCT procedure, regardless of L. plantarum usage.L.plantarum was safe and may potentially reduce fecal levels of Enterococcus genus in HSCT candidates; however, it has not showed a significant impact on Gram-Negative MDRO.